Core B, The Physiology Core, is an integrated resource for analysis of cardiovascular structure and function of murine phenotypes. The Core Director, Jeanne James, MD, is a boarded pediatric cardiologist with both clinical and research expertise in echocardiography and noninvasive imaging techniques. Together with Dr. John Lorenz, the Core provides invasive and noninvasive assessment of cardiovascular structure and function as well as creating surgically stressed models in the different mice prepared by the Project Leaders. Various forms of cardiovascular stress such as thoracic aorta constriction, myocardial infarction and continuous |3-adrenergic stimulation through the use of surgically implanted isopumps are all supported. The Core will typically initiate the analyses by high-throughput screening of cardiac structure and function via echocardiography performed in our state-of-the-art barrier facility at the Children's Hospital Research Foundation. Cardiac magnetic resonance imaging will be performed within CCHMC with a focus on determining the extent of fibrosis via delayed enhancement analyses. The Core will ensure that physiological analyses ofthe mouse models will be performed in a consistent and reproducible manner, which is essential for meaningful comparison and contrast ofthe data from the individual Projects. The Core also provides integrated, consistent statistical support for all investigators through the Heart Institute's centralized servicesi which is staffed by four, PhD level statisticians. All Projects will use this Core. RELEVANCE (See instructions): This Core coordinates whole animal and whole organ physiology for the Program Project Grant.